rear mounted gearbox

[takai]

When i was living in the UK there was a guy who was running a Mini Clubman with a R1 engine, 6spd gearbox, tiny driveshaft, and then a lightweight live axle diff. FR setup.

Went like absolute stink.

[web]

The Volvo setup uses a front mounted clutch. It's easy to bolt a tailshaft straight to the crankshaft, but what's gonna support the flywheel in the back?

I vote mid engine, of the flat and under-floor variety. Just a raised floor, not complete loss of use of the back of the car. Look at how the VW vans do it. Only you'll be doing the same on the correct side of the rear axle. You'd gain space at the front too. Weigh the nose down with fuel tank, battery, spare tire and such and it will handle just fine.

[WDE_BDY]

Realistically, you will need to build a full chassis under it or tie it all together with a cage. Oz legalities are probably screwed for this anyway as the firewall and gearbox tunnel are still going to need massive cutting no matter where you fit the gearbox. However in NZ I have seen a small block chev powered RWD Mini and there was one on Trademe recently with full cage and mid-mounted Honda V-Tec motor (think it was a B16A). Road legal for either is not an issue if built right so maybe shift countries.

Callum

[TooF]

just off the top of my head the porsche 944 uses a rear mount transaxle (?)

[rolleraction]

I personally would go with a large Bike engine, fitted in the front but north south , not east west, the same as they are fitted to a Aussie racer. The Aussie's weigh about 450Kg and the power to weight ratio with a 1200cc bike engine is similar to a V8 supertaxi.. So transposing that idea into your van, performanve would still be very good. The aussie racers also use a modified toyoa live axle rear end with custom ratio CW & pinion and they use 13 inch rims too, not too far larger than your mini wheel size really..5 speed sequential shift would be fun too!

[WDE_BDY]

That used a cut down Toyota 4 speed in order to get a reverse gear. Most other reverse options when using a motorbike box are bloody expensive, rwally shit or both.

Callum

[rolleraction]

Go here for a look -------> http://www.aussieracingcars.com.au/cars.htm

Oh yeah,,good point... reverse would be an issue.
They use starter motors to reverse, but only after a spin or some other 'urgent' requirement to go backwards. Not a very good 'daily' solution.....

[jonathan yee]

WEB...dunno how they support the fly wheel but thats how the alfas and porsches have it. what volvo had the setup your talking about? sounds ideal.

oldcorrollas? what inherant weakness? i thought they used them in the porsche 924's behind big 8cyl audi engines and i think most ferrarri's have transaxles tho they are fitted directly to the side of the engine.

dont like the bike engine ideas. they were only made to propel a sub 300kg vehicle.

the mini's have a seperate rear subframe which i'm hoping/thinking can be modified to hold the tranny and susp mods.

anyhow, thanks for ideas/thoughts, anyone have more first hand exp with rear transaxles?

[takai]

Uh, the bike engine might be made for a sub 300kg vehicle, but as the Locost guys have proven its bloody capable of propelling vehicles weighing much more

[WDE_BDY]

The Starlet picture I posted are of a car that weighs around 700kg plus driver, it is extremely quick with a standard Hyabusa motor and has been smashing hillclimb and bent sprint records in the 1300cc class.

Callum

[Jt_70R]

Ive seen a mk.2 escort somewhere with a 1300 hyabusa. had an interesting spaceframe thing (much like the bike frame i guess) around the motor instead of regular type mounts. whole engine and box could be lifted out as one.

[takai]

http://locostusa.com/forums/viewtopic.php?f=35&t=2837
Thats a very good example of a Locost R1 engined build. Oh and some bloody sexy welding too

[rolleraction]

Great Link Takai.. I jizzed myself over that.. how cool.......!

[Duk]

I thought I'd add some info here because I own an Alfa Romeo 75 V6 with it's rear mounted transaxle.

The Alfa arrangement goes engine-tailshaft-clutch-gearbox-diff.

The Porsche 924/944 use the same arrangement, but they are like their rear engine transaxles where the gearbox is behind the diff, not in front like the Alfa set up.

Alfa transaxles aren't renound for their strength, with the best being the later model 3ltr V6 1s. They are also prone to pretty bad synchro wear, so doing the ol' double clutch down changes becomes second nature after a while.

Another thing you'll want to keep in mind, the Alfa tailshaft uses 3 flexable rubber couplings in their 2 piece taishaft. I have read of a bloke that built a tailshaft for his (4 cyl) race car, and he used 3 uni joints in his design. What he found out was that the tailshaft acted as kind of like a long 2.5" diameter drum at certain engine speeds as the pulsations from the engine on each power stroke rung thru the tailshaft. It was so bad, this bloke redesigned his tailshaft to include a flexable coupling.

[RONA]

i thought they used them in the porsche 924's behind big 8cyl audi engines and i think most ferrarri's have transaxles tho they are fitted directly to the side of the engine.

924 were 4 Cylinder.

928's were the V8 & manual ones are quite rare.